If someone's picking Sejuani in ranked, its probably because they're good with her. Would you rather them play a "top tier" junglier even if they aren't as comfortable with them? If they win more games with Sej then they should play Sej. Simple as that.

Moragan throws her ultimate in your hole team, Zhyonia activated, cant do a ****. Ali jump in it, Pulverize and headbutt the adc to his team. Shen protect his by giving him a 800 shield while you are still stunned by this Pulveriz after this ultimate from Morgana, Blitz jump in it, ultimate, you are all silenced. The adc jump in it and clear the now weak team that you are.

And then the enemy team picks Blitzrank, Shen, Morganna, and Alistar. All because you wasted a ban on someone who doesn't need to be banned.

I have noticed that when I leave out some of these champs (except blitz) people who arent amazing with these champs pick them and end up costing their team the game. I NEVER ban shen, morg, ali, amumu. Everytime I am the captain (and i did these troll bans) I have won the game because I would ban Jax, Lee sin, blitz. etc. This would leave so many "op" champs open that they would try to fit them all in like morg mid/supp, shen top/jungle, mumu jungle etc. and these guys think they can play them to their fullest potential but they cant.

Moragan throws her ultimate in your hole team, Zhyonia activated, cant do a ****. Ali jump in it, Pulverize and headbutt the adc to his team. Shen protect his by giving him a 800 shield while you are still stunned by this Pulveriz after this ultimate from Morgana, Blitz jump in it, ultimate, you are all silenced. The adc jump in it and clear the now weak team that you are.

Yea...works really well in theory. By that logic Master Yi can just ult, run out of range of morg's ult then come back and kill her. Are you telling me that Master Yi is a counter for Morg?
And yes with his speed, he can easily dodge morg's snare.